1. Technical Field
The present invention relates to a hand-held controller connected to a control device for controlling the operating mechanism unit of a machine, and used by being gripped by an operator when the operating mechanism unit is manually controlled.
2. Description of the Related Art
Machine tools, for example, have lighting devices as appropriate for easily performing work when an operator carries out various tasks, such as checking machining of workpieces, and checking operations of tools and the workpieces. One example that is known of such a lighting device is that disclosed in Japanese Unexamined Pat. App. Pub. No. 2005-28461.
The lighting device is made up of: a bowl-shaped lighting cover that is open at either end, with the upper portion having a small diameter, and the lower portion having a large diameter; an illumination lamp formed into a loop and arranged coaxially with the upper opening and the lower opening of the lighting cover; a bracket for supporting the illumination lamp on the inner surface of the lighting cover; a magnet provided on an upper-end surface of the lighting cover; and a protection member for covering the illumination lamp to protect it from chips and cutting fluid. In a machine tool such as a vertical machining center, the lighting device is attached to a lower-end surface of the spindle head by means of the magnet, with the spindle and the tool being inserted through the upper and lower openings of the lighting cover, and the central aperture of the illumination lamp.
According to this lighting device, the illumination lamp is attached to the machine tool with the spindle inserted into the central aperture of the illumination lamp, wherein the lamp is in a placement in which the light shining from the lamp is shielded by the spindle and the tool, preventing shadows from the spindle and the tool from being produced on the surface of the workpiece, which results in an environment that facilitates work for the operator.
However, the above described conventional lighting device, since it is fixed to the machine tool, has entailed the problem that due to other structures (the supply nozzle for supplying cutting fluid to a contact portion between the tool and the workpiece, for example) arranged between the illumination lamp and the workpiece, shadows are bound to be produced on the surface of the workpiece, creating areas where visual checking is impaired, and has also entailed the problem that it is bright directly below and around the lighting device, yet dark in areas apart from that, which can impair an operator's work.
Furthermore, although the areas where visually checking is hampered can be prevented by an operator illuminating a desired area with a suitable small portable lighting device, in a situation, for example, in which an operator manually controls a machine tool with a manual pulse generator, a suitable small portable lighting device cannot be employed.